Start with putting a layer of refried beans in the bottom of each cup.
Add a layer of guacamole, then a layer of sour cream, and finally a layer of salsa to each cup.
Next, sprinkle a layer of shredded cheese into each of the cups.
Garnish with the black beans, green onion, and tomatoes by putting a few of each on top of each cup. Squeeze a bit of lime juice over each cup if desired.